I like react-bootstrap since it already solved the rough edges of integrating bootstrap into react. So I definitely would go for react-bootstrap.
The only downside is that react-bootstrap is based on bootstrap v3 and not the upcoming v4, so you're surely looking for a migration in the future.
zeit.co are doing an amazing work with "now", but some parts are still missing, like logs.
I wanted to create a free & simple logger that can be used before integrating a more mature service like loggly/papertrail